Magneto-electric point scattering theory for metamaterial scatterers

TL;DR

This paper introduces a comprehensive analytical model for anisotropic magneto-electric scatterers, accounting for reciprocity and damping, to better understand their optical responses and interactions.

Contribution

The paper develops a fully analytical point scattering model for anisotropic magneto-electric dipoles, including reciprocity and damping effects, applicable to complex metamaterial scatterers.

Findings

Model accurately predicts scattering and extinction cross sections.

Reveals how structural chirality can emerge in non-chiral scatterers.

Describes coupling mechanisms in split ring dimers.

Abstract

We present a new, fully analytical point scattering model which can be applied to arbitrary anisotropic magneto-electric dipole scatterers, including split ring resonators (SRRs), chiral and anisotropic plasmonic scatterers. We have taken proper account of reciprocity and radiation damping for electric and magnetic scatterers with any general polarizability tensor. Specifically, we show how reciprocity and energy balance puts constraints on the electrodynamic responses arbitrary scatterers can have to light. Our theory sheds new light on the magnitude of cross sections for scattering and extinction, and for instance on the emergence of structural chirality in the optical response of geometrically non-chiral scatterers like SRRs. We apply the model to SRRs and discuss how to extract individual components of the polarizability matrix and extinction cross sections. Finally, we show that our model describes well the extinction of stereo-dimers of split rings, while providing new insights in the underlying coupling mechanisms.